Where should these wires be going?

[tjr818]

I have a new to me CD27 with a Yanmar YSM8 that seems to be running great, however when I started looking around I found several wires that seem to be disconnected. Can anyone give me some advice? Here are the pictures:
[img]http://i1218.photobucket.com/albums/dd4 ... nected.jpg[/img]
and
[img]http://i1218.photobucket.com/albums/dd4 ... owhere.jpg[/img][/img]

[camroll]

In the bottom picture I'm pretty sure that's an oil pressure switch. Typically on Yanmars the oil pressure is a blue wire. This sends a signal to your control panel to set off a warning light for low oil pressure.

[Ray Garcia]

Actually the second picture is the water temp probe. If it is disconnected you definitely want to connect it again. The previous owner may have disconnected it due to malfunction. Overheating this motor (YSM8) will surely shorten its life. The oil pressure probe is towards the front of the engine.

I believe the two wires towards the back are for a tachometer probe that would be located on the flywheel case. I have never seen a tachometer installed on this engine here in the states.

If you are not sure of the maintenance schedule I would suggest the following:
Oil Change
Engine Zinc
Secondary fuel filter on the engine
Water pump impeller
Thermostat

These items are all inexpensive and easy to complete yourself. It will surely add not only to your piece of mind but to the life of the engine.

Great boat, tough engine.

Good luck with your new 27.

[tjr818]

In the second picture my question is about the second lead that is not connected. The one wire seems to head back toward the engine panel in the cockpit, but the other lead has a butt connector of some sort, but nothing is connected to it.
I will be tracing wires next weekend (if the rain stops).
In the first picture I don't see where the two "disconnected" wires could possibly connect. Would some installs have gauges rather than idiot lights? Are these wires connected to simple switches or to sending units? My boat does not have gauges nor does it have a tach.

[jcmacleod]

The first picture the wires are for a tach, which this engine does not typically have hooked up. The second is the temp sending unit

[tjr818]

The first picture the wires are for a tach, which this engine does not typically have hooked up. The second is the temp sending unit

Thanks. What would it take to hook up a tach? And is it worthwhile? I have been looking at the Tiny Tach.